Orthodontic treatment (commonly known as braces) can be a lengthy process to re-align your teeth to a more functional and aesthetic position. Once the orthodontic devices are removed, however, the treatment isn't finished. Wearing a retainer is the final step to ensuring that the re-alignment doesn't eventually fail. It's designed to do just what its name implies — to “retain” the teeth's new position and prevent a relapse to the old.

This can happen because of the way teeth fit into the jaw bone. The teeth are joined to the bone by the periodontal ligament, which works somewhat like a hammock: the ligament's fibers act like threads that fit into the tooth on one side and into the bone on the other, and hold the teeth in place.

As living tissue, the ligament's cell structure is dynamic and can adapt to the gentle pressure applied by an orthodontic device. However, once this pressure subsides after the device is removed “muscle memory” can cause the ligament to resist the new position and pull the teeth back to their original setting. The retainer helps hold the teeth in the new position while the bone and ligament continue to mature and stabilize around the teeth.

There are two basic types of retainers; the one recommended for you will depend on your age and the extent of your orthodontic treatment. One type is a removable device that is typically worn around the clock initially, but may eventually only need to be worn at night or for even a lesser interval of time. The other type is attached permanently behind the teeth and can only be removed by an orthodontist. Permanent retainers have the benefit of not being as visible as the removable type, and there's no bother with putting them in and taking them out.

You may consider wearing a retainer a nuisance especially after months of orthodontic treatment. But consider it the last lap in a long race — only by finishing can you achieve that winning smile.